What to drink and eat during a heatwave
Steady sipping beats catching up, cool beats ice-cold, and the meal you cook matters as much as the food you eat.
Food and drink matter more than usual when your body is already working hard to stay cool. Sweating costs you water and salts continuously, and the meals that feel normal in spring can add real load in the middle of a hot week.
The hydration checklist
- Sip water regularly through the day, before you feel thirsty. Thirst lags behind actual need, especially in older adults
- Avoid heavy hot meals and alcohol when it is very warm. Both make your body work harder at the worst moment
- Prefer cool drinks over ice-cold ones. Very cold liquids can cause stomach cramps when you are overheated
- Light salads and fruit are easier on your body, and much of your fluid intake can come from what you eat
- Replace salts, not just water, if you have been sweating heavily for days
Why steady beats catching up
Drinking a large volume at once mostly passes through you. Your body can only absorb so much at a time, and a litre downed in one go does less good than the same litre spread across an afternoon.
A glass every hour is the boring answer, and it is the one that works. If you find that hard to remember, keep a filled bottle in whichever room you actually sit in.
Foods that carry water
Watermelon, cucumber, tomatoes, peaches, courgettes, and leafy salads are mostly water and require no cooking. Chilled soups do the same job. This is a week where cold plates, bread, cheese, and fruit are a reasonable dinner.
The kitchen is a heat source
An oven running for an hour can noticeably warm a small flat, and it does so during the exact hours when you are trying to keep heat out. So can a hob under a large pan, a dishwasher on a hot cycle, and a tumble dryer.
Where you can, shift cooking to the cool hours, cook once for several meals, or skip it. This is the same logic as phase one of the heat cycle: during the day, everything that produces heat indoors works against you.
About salt and sugar
If you have been sweating for several days, plain water alone can leave you short on electrolytes. Ordinary food usually covers it: a salty snack, olives, cheese, or a normally salted meal will do. Sports drinks are not required for sitting out a heatwave at home, and their sugar content is not helping you.
Alcohol deserves its own line. It is a diuretic, it disrupts sleep on hot nights, and it blunts your judgement about how you are coping. Coffee in normal amounts is less of a problem than it is often made out to be, but it is not a substitute for water.
Who needs watching
Older adults feel thirst less reliably. Young children dehydrate faster relative to their size. Anyone on diuretics or medication affecting fluid balance should follow their doctor’s guidance rather than general advice. During a long heatwave, checking in on someone is worth more than any tip on this page.